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Diffstat (limited to 'libskrift.h')
| -rw-r--r-- | libskrift.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/libskrift.h b/libskrift.h new file mode 100644 index 0000000..5c2e937 --- /dev/null +++ b/libskrift.h @@ -0,0 +1,183 @@ +/* See LICENSE file for copyright and license details. */ +#ifndef LIBSKRIFT_H +#define LIBSKRIFT_H 1 + +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> + +#if defined(__GNUC__) +# define _LIBSKRIFT_GCC_ONLY(...) __VA_ARGS__ +#else +# define _LIBSKRIFT_GCC_ONLY(...) +#endif + + +#define LIBSKRIFT_RENDERING_STRUCT_VERSION 0 + +#define LIBSKRIFT_NONE 0 + +typedef struct libskrift_context LIBSKRIFT_CONTEXT; +typedef struct libskrift_font LIBSKRIFT_FONT; +typedef uint_least32_t libskrift_codepoint_t; + + +enum libskrift_subpixel_order { + LIBSKRIFT_OTHER, /* LIBSKRIFT_NONE */ + LIBSKRIFT_RGB, + LIBSKRIFT_BGR, + LIBSKRIFT_VRGB, + LIBSKRIFT_VBGR +}; + +enum libskrift_smoothing { + LIBSKRIFT_MONOCHROME, /* LIBSKRIFT_NONE */ + LIBSKRIFT_GREYSCALE, + LIBSKRIFT_SUBPIXEL +}; + +enum libskrift_hinting { + LIBSKRIFT_UNHINTED = 0, /* LIBSKRIFT_NONE */ + LIBSKRIFT_SLIGHT = 25, + LIBSKRIFT_MEDIUM = 50, + LIBSKRIFT_FULL = 100 +}; + +enum libskrift_rendering_flags { + LIBSKRIFT_CORRECT_GAMMA = 0x0001, + LIBSKRIFT_REMOVE_GAMMA = 0x0002, + LIBSKRIFT_Y_INCREASES_UPWARDS = 0x0004, /* SFT_DOWNWARD_Y otherwise */ + LIBSKRIFT_FLIP_TEXT = 0x0008, + LIBSKRIFT_MIRROR_TEXT = 0x0010, + LIBSKRIFT_MIRROR_CHARS = 0x0020, + LIBSKRIFT_TRANSPOSE_TEXT = 0x0040, + LIBSKRIFT_TRANSPOSE_CHARS = 0x0080, + LIBSKRIFT_NO_LIGATURES = 0x0100, + LIBSKRIFT_ADVANCE_TO_GRID = 0x0200, + LIBSKRIFT_REGRESS_TO_GRID = 0x0400, /* Combine with LIBSKRIFT_ADVANCE_TO_GRID for closest alternative */ + LIBSKRIFT_USE_SUBPIXEL_GRID = 0x0800 +}; + +struct libskrift_rendering { + int struct_version; + enum libskrift_subpixel_order subpixel_order; + enum libskrift_smoothing smoothing; + enum libskrift_hinting hinting; + enum libskrift_rendering_flags flags; + double horizontal_dpi; + double vertical_dpi; + double kerning; + double interletter_spacing; + double prestroke_transformation_rotation[4]; + double left_transformation[6]; + double right_transformation[6]; + double top_transformation[6]; + double bottom_transformation[6]; + double poststroke_transformation_rotation[4]; + double char_transformation[6]; + double text_transformation[6]; +}; + +struct libskrift_glyph { + double advance; + int16_t x; + int16_t y; + uint16_t width; + uint16_t height; + size_t size; + uint8_t image[]; +}; + +struct libskrift_saved_grapheme { + libskrift_codepoint_t cp; + size_t len; +}; + + +#define LIBSKRIFT_DEFAULT_RENDERING {\ + .struct_version = LIBSKRIFT_RENDERING_STRUCT_VERSION,\ + .subpixel_order = LIBSKRIFT_NONE,\ + .smoothing = LIBSKRIFT_GREYSCALE,\ + .hinting = LIBSKRIFT_FULL,\ + .flags = 0,\ + .horizontal_dpi = (double)1920 * 254 / 5180,\ + .vertical_dpi = (double)1200 * 254 / 3240,\ + .kerning = 1,\ + .interletter_spacing = 0,\ + .prestroke_transformation_rotation = {1, 0, 0, 1},\ + .left_transformation = {1, 0, 0, 0, 1, 0},\ + .right_transformation = {1, 0, 0, 0, 1, 0},\ + .top_transformation = {1, 0, 0, 0, 1, 0},\ + .bottom_transformation = {1, 0, 0, 0, 1, 0},\ + .poststroke_transformation_rotation = {1, 0, 0, 1},\ + .char_transformation = {1, 0, 0, 0, 1, 0},\ + .text_transformation = {1, 0, 0, 0, 1, 0},\ +} + +#define LIBSKRIFT_NO_SAVED_GRAPHEME {0, 0} + + +_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__))) +inline double +libskrift_calculate_dpi(double pixels, double millimeters) +{ + return pixels * 254 / 10 / millimeters; +} + +_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__))) +inline double +libskrift_inches_to_pixels(double inches, const struct libskrift_rendering *rendering) +{ + return inches * rendering->vertical_dpi; +} + +_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__))) +inline double +libskrift_millimeters_to_pixels(double millimeters, const struct libskrift_rendering *rendering) +{ + return millimeters * 10 / 254 * rendering->vertical_dpi; +} + +_LIBSKRIFT_GCC_ONLY(__attribute__((__const__, __warn_unused_result__))) +inline double +libskrift_points_to_pixels(double points, const struct libskrift_rendering *rendering) +{ + return points / 72 * rendering->vertical_dpi; +} + + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__))) +int libskrift_open_font_file(LIBSKRIFT_FONT **, const char *); + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__))) +int libskrift_open_font_mem(LIBSKRIFT_FONT **, const void *, size_t); + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__))) +int libskrift_open_font_fd(LIBSKRIFT_FONT **, int); + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__))) +int libskrift_open_font(LIBSKRIFT_FONT **, FILE *); + +void libskrift_close_font(LIBSKRIFT_FONT *); + + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2)))) +int libskrift_create_context(LIBSKRIFT_CONTEXT **, LIBSKRIFT_FONT *, const struct libskrift_rendering *, double); + +void libskrift_free_context(LIBSKRIFT_CONTEXT *); + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__, __returns_nonnull__, __warn_unused_result__, __const__))) +const struct libskrift_rendering *libskrift_get_rendering_settings(LIBSKRIFT_CONTEXT *); + + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__))) +int libskrift_get_grapheme_glyph(LIBSKRIFT_CONTEXT *, libskrift_codepoint_t, double, double, struct libskrift_glyph **); + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__(1, 2, 6)))) +ssize_t libskrift_get_cluster_glyph(LIBSKRIFT_CONTEXT *, const char *, struct libskrift_saved_grapheme *, + double, double, struct libskrift_glyph **); + +_LIBSKRIFT_GCC_ONLY(__attribute__((__nonnull__))) +int libskrift_merge_glyphs(LIBSKRIFT_CONTEXT *, struct libskrift_glyph *, struct libskrift_glyph *, struct libskrift_glyph **); + +#endif |